From 2852ca7fba9f77b204f0fe953b31fadd0057c936 Mon Sep 17 00:00:00 2001
From: David Gow <davidgow@google.com>
Date: Fri, 1 Jul 2022 16:47:41 +0800
Subject: [PATCH] panic: Taint kernel if tests are run
Most in-kernel tests (such as KUnit tests) are not supposed to run on
production systems: they may do deliberately illegal things to trigger
errors, and have security implications (for example, KUnit assertions
will often deliberately leak kernel addresses).
Add a new taint type, TAINT_TEST to signal that a test has been run.
This will be printed as 'N' (originally for kuNit, as every other
sensible letter was taken.)
This should discourage people from running these tests on production
systems, and to make it easier to tell if tests have been run
accidentally (by loading the wrong configuration, etc.)
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
Documentation/admin-guide/tainted-kernels.rst | 1 +
include/linux/panic.h | 3 ++-
kernel/panic.c | 1 +
3 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/Documentation/admin-guide/tainted-kernels.rst b/Documentation/admin-guide/tainted-kernels.rst
index ceeed7b0798da..7d80e8c307d14 100644
--- a/Documentation/admin-guide/tainted-kernels.rst
+++ b/Documentation/admin-guide/tainted-kernels.rst
@@ -100,6 +100,7 @@ Bit Log Number Reason that got the kernel tainted
15 _/K 32768 kernel has been live patched
16 _/X 65536 auxiliary taint, defined for and used by distros
17 _/T 131072 kernel was built with the struct randomization plugin
+ 18 _/N 262144 an in-kernel test has been run
=== === ====== ========================================================
Note: The character ``_`` is representing a blank in this table to make reading
diff --git a/include/linux/panic.h b/include/linux/panic.h
index e71161da69c4b..c7759b3f20452 100644
--- a/include/linux/panic.h
+++ b/include/linux/panic.h
@@ -68,7 +68,8 @@ static inline void set_arch_panic_timeout(int timeout, int arch_default_timeout)
#define TAINT_LIVEPATCH 15
#define TAINT_AUX 16
#define TAINT_RANDSTRUCT 17
-#define TAINT_FLAGS_COUNT 18
+#define TAINT_TEST 18
+#define TAINT_FLAGS_COUNT 19
#define TAINT_FLAGS_MAX ((1UL << TAINT_FLAGS_COUNT) - 1)
struct taint_flag {
diff --git a/kernel/panic.c b/kernel/panic.c
index a3c758dba15ab..6b3369e210261 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -428,6 +428,7 @@ const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = {
[ TAINT_LIVEPATCH ] = { 'K', ' ', true },
[ TAINT_AUX ] = { 'X', ' ', true },
[ TAINT_RANDSTRUCT ] = { 'T', ' ', true },
+ [ TAINT_TEST ] = { 'N', ' ', true },
};
/**
--
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